Java
The document provides an overview of key concepts in Java including: - Java is an object-oriented, platform independent language that is simple, secure, and allows for multi-threaded, high performance applications. - Objects have states and behaviors defined by classes. Methods define behaviors and instance variables define states. - Programming conventions like case sensitivity, class/method naming, and file naming are important to follow. - The main() method marks the starting point of a Java program and its modifiers and parameters are explained. - Object-oriented principles like abstraction, encapsulation, inheritance, and polymorphism are discussed at a high-level. - Additional concepts covered include threads, exceptions, constructors, packages, and
![Simple Program
class HelloWorldApp {
public static void main(String[] args) {
HelloWorldApp hello = new HelloWorldApp();
hello.sayHello();
}
public void sayHello(){
System.out.println(Hello);
}
}
O/P : Hello
Rajavel D Java IITB-CSE-Internship 2013](https://image.slidesharecdn.com/java-130514103014-phpapp02/85/Java-6-320.jpg)
Java
- 1. 13-05-2013Rajavel DRajavel D Java Summer Internship 2013 (Indian Institute of Technology Bombay)
- 2. Java Object-Oriented Platform independent Simple Secure Multi-threaded High Performance Rajavel D Java IITB-CSE-Internship 2013
- 4. Basic terms Object - Objects have states and behaviors. Class - A class can be defined as a blue print that describe the behaviors/states that object. Methods - A method is basically a behavior. Instance Variables - States of an objects, each object has its unique set of instance variables. Rajavel D Java IITB-CSE-Internship 2013
- 5. Keep in Mind Case Sensitivity - Hello and hello would have different meaning in Java. Class Names - For all class names the first letter should be in Upper Case. Example : class MyFirstJavaClass Method Names - All method names should start with a Lower Case letter and each inner word's first letter should be in Upper Case. Example : public void myMethodName() Program File Name - Name of the program file should exactly match the class name. Rajavel D Java IITB-CSE-Internship 2013
- 6. Simple Program class HelloWorldApp { public static void main(String[] args) { HelloWorldApp hello = new HelloWorldApp(); hello.sayHello(); } public void sayHello(){ System.out.println(Hello); } } O/P : Hello Rajavel D Java IITB-CSE-Internship 2013
- 7. Modifiers and Variables Access Modifiers : default, public , protected, private Non-access Modifiers : final, abstract, static, strictfp, synchronized and volatile Type of variables in Java: Local Variables Class Variables (Static Variables) Instance Variables (Non static variables) Rajavel D Java IITB-CSE-Internship 2013
- 8. public static void main ? java program processing starts from the main() method. Public ? Static? Void? Rajavel D Java IITB-CSE-Internship 2013
- 9. Object Oriented Principles Abstraction Hiding the implementation (abstract class and interface) Encapsulation Wrapping up of data into single unit. (data hiding) Inheritance Reusable the properties of existing class Polymorphism Overloading and Overriding Rajavel D Java IITB-CSE-Internship 2013
- 10. Thread Create Thread by implements Runnable interface or extends Thread class Rajavel D Java IITB-CSE-Internship 2013
- 11. Exception Handling Problem that arises during the execution of a program. try{} catch{} finally{} Rajavel D Java IITB-CSE-Internship 2013
- 12. Some important concepts Constructor Package Multithreading Synchronized This keyword finally Rajavel D Java IITB-CSE-Internship 2013
- 13. Any Doubts ??? Rajavel D Java IITB-CSE-Internship 2013
- 14. References http://download.oracle.com/javase/tutorial/ http://www.tutorialspoint.com/java www.java2s.com/Tutorial/Java/CatalogJava.h tm Rajavel D Java IITB-CSE-Internship 2013